Laser machining of micro-notches for fatigue life

Evaluation of fatigue life for engineering components used in structurally demanding applications is very important. Micro-notches need to be fabricated on test specimens to replicate surface defects for experimental determination of fatigue life studies. A study for generating micro-notches on engineering materials like stainless steel and aluminum alloys using a nano-second pulsed fiber laser has been carried out and results are reported in this paper. The effect of different process parameters on the notch size has been studied. The mechanism of material removal in forming the notches has been studied as a function of laser fluence. The development of the notch by the interaction of laser pulses has also been studied by monitoring the reflected light from the interaction region.